The present invention relates in general to a torsional vibration damper, and in particular to a torsional vibration damper of a type having a primary structural unit and a secondary structural unit which are rotatable relative to one another and linked to each other by a spring arrangement including at least one thrust piston, whereby the flow of force between the thrust piston of the spring arrangement and at least the secondary structural unit is realized, at least at certain angles of rotation, via an outer surface area that engages the thrust piston.
Such a torsional vibration damper is known, for example, from German Pat. No. 195 44 832 A1. In this torsional vibration damper, a driving disk overlaps a driven disk, and is formed at the inside of the overlapping part with radial pockets spaced about the periphery and having an outer surface area which extends in the direction of their peripheral ends in a slightly wedged-shaped manner toward the driving disk. The outer surface area of the driving disk has a polygonal cross section, and the pockets of the driving disk accommodate pairs of wedge-shaped thrust pistons separated from each other by compression springs. Therefore, the force flows from the driving disk via the thrust pistons and their compression springs to the polygonal outer surface area of the driven disk.